More genes seem to precede the need for themselves. A team at the University of Wisconsin found that unicellular choanoflagellates express members of protein families previously found only in multicelled animals:
"In marked contrast to their simple lifestyle, choanoflagellates express members of a wide variety of protein families involved in animal cell interactions, including cadherins, C-type lectins, tyrosine kinases, and a G protein-coupled receptor, as well as several multidomain polypeptides that contain protein-protein interaction domains involved in signaling and adhesion in animals [such as the epidermal growth factor motif, Src homology 2 domain, tumor necrosis factor receptor domain, and sushi or complement control protein domain]."
King et al. suspect more. They write, "We have sampled just a fraction of the choanoflagellate proteome. The diversity of choanoflagellate proteins predicted to function in cell interactions suggests that additional proteins shared exclusively with animals will be discovered through sequencing the entire choanoflagellate genome. ...It may then be possible to determine whether entire regulatory pathways linking receptor-based signaling inputs to gene regulation and cell behavior predate the origin of animals." As darwinists, they reason, "The discovery of multiple signaling and adhesion gene family members in choanoflagellates demonstrates that key proteins required for animal development evolved before the origin of animals." If so, they wonder, "The existence in unicellular choanoflagellates of proteins used for cell adhesion and signal transduction in animals prompts the question of their ancestral function in the progenitor of animals and choanoflagellates." You bet it does. Here they introduce a list of speculations.

Reconstructing evolution that happened hundreds of millions of years ago from clues in today's genomes requires substantial faith. However, if the method is valid, we think the evidence in this study supports cosmic ancestry, whereunder existing species acquire new genetic programs by gene transfer. Only after acquisition will the programs be expressed in new phenotypes. If, on the other hand, new programs are gradually composed by the darwinian method, the ones in this study must have originally served purposes different from the ones they serve in animals today. To account for this phenomenon darwinians must invent more stories.

The role of gene transfer in evolution is greater than previously thought. A team of US biologists reached this conclusion after a study of transferred mitochondrial genes in plants. They write, "Conventional genes are subject to evolutionarily frequent HGT during plant evolution and... plants can donate DNA horizontally to other plants." "Eukaryotic genomes regularly acquire genes by means of horizontal events that are relatively recent, datable, and definable as to donor and recipient." "We believe the five cases reported here are merely the tip of a large iceberg of mitochondrial HGT in plants." "It seems likely that plant nuclear genomes are also significantly affected by HGT." And they wonder, "Is HGT driven predominantly by potential vectoring agents such as viruses, bacteria, fungi, insects, pollen or even meteorites; or by the transformational uptake of plant DNA released into the soil; or by unrelated plants occasionally grafting together?" [Thanks, Hans-Peter Wheeler.]

Introns can cause new stretches of DNA to be precisely inserted into genomes. While hints of this capability were already known, introns seem even more remarkable now, according to a review in Science. "Introns serve as templates for making other proteins. Among these are spectacular enzymes that inject new stretches of DNA into precisely defined spots in a genome." Tools like this one would be necessary for the integration of new genetic programs, as in cosmic ancestry.

The article is also informative about inteins [see figure], which are similar to introns by being sequences that are ulimately removed. But inteins are edited out of amino acid sequences (after translation), whereas introns are edited out of mRNA sequences (before translation).

An in-depth commentary on the Viking mission's tests for life on Mars is posted. "We have received biology data that we believe to be good data...," said NASA's Jim Martin at the 1:30 pm news briefing on 31 July 1976. And on 7 August, NASA's Norman Horowitz said, "There's a possibility that this is biological, [but] there are many other possibilities that have to be excluded." Arguments for nonbiological interpretations of the Viking data are clearer here than elsewhere. [Thanks, Marsbugs.]

Horizontal gene transfer as a significant evolutionary driver may require an addendum to the Darwinian synthesis. So say commentators Raymond and Blankenship in PNAS about a study of 78 plastid-targeted proteins from a eukaryotic alga. It showed, "Even by conservative measures, ~21% of these genes have likely been acquired by HGT." Furthermore, "These horizontally transferred genes span a varied swath of functions...."

"Most intriguingly, two of the genes from [Archibald et al.'s] analysis indicate HGT from different bacteria, significant not only as an example of prokaryote-to-eukaryote gene transfer but also because these acquired genes initially would have not had the proper leader sequence for import into the plastid. Whether the appropriate targeting sequence was incorporated de novo through gene conversion or some other mechanism of homologous or orthologous replacement is not clear, but this remarkable finding certainly invokes new ideas on how genes are assimilated into a genome." Finally, "It now seems clear that many organisms, eukaryotes and prokaryotes, are certainly able to mimic evolutionary jumps through HGT." J.M. Archibald, M.B. Rogers, M. Toop, K.-i Ishida and P.J. Keeling, "Lateral gene transfer and the evolution of plastid-targeted proteins in the secondary plastid-containing alga Bigelowiella natans" [abstract], p 7678–7683 v 100, Proc. Natl. Acad. Sci. USA, 24 June 2003. Jason Raymond and Robert E. Blankenship, "Horizontal gene transfer in eukaryotic algal evolution" [title page], p 7419-7420 v 100, Proc. Natl. Acad. Sci. USA, 24 June 2003.

The evolutionary importance of insertions and deletions gets more notice from an international team who compared orthologous sequences from the human and chimp genomes (1.87 and 1.75 million nucleotides, respectively). They conclude, "these data suggest that evolution may have used the mechanistically more drastic indels instead of the more subtle single-nucleotide substitutions for shaping the recently emerged primate species." Tatsuya Anzai et al., "Comparative sequencing of human and chimpanzee MHC class I regions unveils insertion/deletions as the major path to genomic divergence" [abstract], p 7708-7713 v 100, Proc. Natl. Acad. Sci. USA, 24 June 2003. Human Genome Search... is a related CA webpage.

These recent developments are consistent with cosmic ancestry, we suggest. In the new theory, evolutionary advances are made possible when new genetic programs are acquired by horizontal gene transfer. This paradigm shift has already been accepted for prokaryotes; now evidence for it among eukaryotes is accumulating. Naturally, it requires the insertion of large blocks of code. Then, placing imported genes or gene fragments into designated reception areas would make them easier to retrieve later, and it would reduce the risk of damage to the receiving genome. How the genome would then assimilate the new software is not known, but the installation system would probably include mechanisms that are remarkable and intriguing to darwinists. Viruses... is a CA webpage about horizontal gene transfer. [Next-What'sNEW about HGT-Prev]

June 10

A live online chat about panspermia with Brig Klyce, this website's author, will take place at 9PM Eastern on Thursday, 19 June 2003 (if all the software works!) Visit the link below and download an applet to participate in or to watch the discussion. The chat is sponsored by The International Society for Complexity, Information, and Design, a creationist-oriented group. We welcome this opportunity to discuss panspermia.

European Mars Express space probe is on the way to Mars. Due to arrive there in late December, "This first European Space Agency probe to head for another planet will enter an orbit around Mars, from where it will perform detailed studies of the planet's surface, its subsurface structures and its atmosphere. It will also deploy Beagle 2, a small autonomous station which will land on the planet, studying its surface and looking for possible signs of life, past or present."

Mud flows on Mars? "Satellite photos of a bright dune in the Martian southern hemisphere show remarkable details of an unusual erosion pattern. Unlike rocky avalanches found elsewhere, the dune flows suggest to two German scientists that for a few summer noon hours, liquid water may carve up the dunes in a region called Russell Crater. They ask the question: has mud flowed in the last thousand years on Mars?"

D. Reiss and R. Jaumann, "Recent debris flows on Mars: Seasonal observations of the Russell Crater dune field" [abstract], p 1321 v 30 n 6 Geophys. Res. Lett., 26 March 2003. Is There Martian Mud in Russell Crater?, Astrobiology Magazine, 29 May 2003. Life on Mars! is the related CA webpage. "What'sNEW" there contains over 200 items, most of which are not mentioned on the main What'sNEW page.

More about the Huygens Probe, Europe's mission to Titan, comes from the European Space Agency. ESA says, "Speculations and experiments concerning the origin of life have led to no clear conclusions, despite a hundred years of effort by eminent scientists. How self-sustaining assemblies of nucleic acids, proteins and fats came into existence remains as inexplicable as ever." We welcome this blunt assessment from the orthodox scientists at ESA. Promoting Huygens, they continue, "Space research may break through a log-jam of ideas by identifying the likely chemical precursors that flavoured the primeval soup." ESA says Titan's methane is one of the initial ingredients undergoing solar radiation to make the soup, as the illustration shows. But methane itself is far easier to make biologically than otherwise, as ESA acknowledged recently. After a hundred years of failed effort to model the origin of life, perhaps we ought to consider the alternatives. [Thanks, Kevin Hatfield.]

Revisiting the Miller Experiment of fifty years ago is the subject of an informative essay in today's Science by two prominent origin-of-life researchers, Jeffrey Bada and Antonio Lazcano. The writers acknowlege that Stanley Miller and Harold Urey were probably wrong, in 1953, about Earth's early atmosphere, and they accept the recent evidence that "prebiotic" compounds arrive from space. Most noteworthy to us, however, is that the essay does not even mention the software aspect of the origin-of-life problem.